With the development of mobile phone technologies, people are paying more and more attention to the display function of the mobile phone; especially during the emergence of 3G mobile phone, higher requirements are proposed for the display size of the mobile phone. Touch-screen phones have become a popular trend, especially the phones with touch screens more than 2.8 inch, or 3.0 inch. Based on the occurrence of such big size screen, the existing smart phone now gradually cancels most of the keyboards during designing, but realizes operations of phone menus directly using the touch screen and 2-3 function keys. However, in such case, once the touch screen is damaged or is not convenient to be used and there are only 2-3 functional keys, the operations of the phone menus cannot be realized, and even the basis unlocking, calling and texting cannot be achieved, thus for users that is not convenient.